Microsoft has signed a cross-license patent agreement with Samsung Electronics that grants Microsoft royalties from Samsung's Android-based smartphones and tablets, Microsoft said in a statement on Wednesday.

Microsoft didn't disclose details on how much money Samsung will have to pay Microsoft for every Android-based device it sells. Last year, HTC, which together with Samsung dominate the market for Android-based smartphones, also signed a licensing deal with Microsoft.

In the past three months, Microsoft has signed Android deals with Acer, General Dynamics Itronix, Onkyo, Velocity Micro, ViewSonic and Wistron, Microsoft's general council Brad Smith and deputy general council Horacio Gutierrez wrote in a blog post.

That leaves Motorola Mobility, with which Microsoft is currently in litigation, as the only major Android smartphone manufacturer in the U.S. without a license, they said.

It seems unlikely that Microsoft and Motorola Mobility will agree on a licensing deal without litigation. Motorola Mobility is in the process of being acquired by Google. "Our acquisition of Motorola will increase competition by strengthening Google's patent portfolio, which will enable us to better protect Android from anti-competitive threats from Microsoft, Apple and other companies," Google CEO Larry Page said about the $12.5 billion acquisition.

Smith and Gutierrez had this message for Google in their blog post: "We recognize that some businesses and commentators -- Google chief among them -- have complained about the potential impact of patents on Android and software innovation. To them, we say this: look at today's announcement. If industry leaders such as Samsung and HTC can enter into these agreements, doesn't this provide a clear path forward?"

Samsung signing a deal with Microsoft makes more sense. The company is already busy battling with Apple in courts around the world. Samsung did not reply to questions about the deal.

Also, earlier this week, Samsung announced the Omnia W, its first smartphone based on Windows 7.5, also known as Mango. In addition to the licensing deal, the companies also agreed to cooperate in the development and marketing of Windows Phone, Microsoft said on Wednesday.

Samsung and HTC are close partners to Microsoft, so signing licensing deals make their lives easier, according to Francisco Jeronimo, research manager at IDC.

But, on Tuesday, Samsung joined Intel to help develop Tizen, a new OS that merges MeeGo and Limo. So the company is keeping its options open when it comes to OSes.